Vane pump



Mrch e, 1945. CKE ETAL 2,371,081

VANE PUMP ori inal Filed Feb. 6, 1941 2 sheets-sheet 1 INVENTORS ByWARREN R TUCKER k scones A.WALD|E ATTORNEYS Mafch s, 1945.

W. R. TUCKER ET AL h S y t e e Penman". e, 1945 vans rum Warren R.Tucker and George A. Waldie, Dayton, Ohio, assignors to The HydraulicDevelopment Corp. Inc., W tion of Delaware 11, Del., a corpora- Originalapplication February 6, 1941, Serial No.

Divided and this application Decent "T ber 17, 1941. Serial No. 423,3381 Claim. (01. 103-138) This invention relates to fluid pumps 01' thevane type, and more particularly to fluid pumps which are adapted forcirculating liquids and for producing pressure with said liquids foractuating various operating elements.

In this invention the fluid pump is adapted to pump hydraulic fluid froma storage chamber to a hydraulically actuated device, such as a press,

molding machine or other conventional hydraulically actuated mechanisms.There are many types of pumps which are adapted for placing fluids underpressure, but the types of pumps which have heretofore been used inplacing liquid under pressure have been limited to the radial pistontype of liquid pump. This type of pump produces high pressure withrelatively low power consumption and has been the most efllcient typefor use in producing high fluid pressures for actuating mechanicalpresses requiring high fluid pressures.

In this invention, however, mechanical alterations have been made to avane type of fluid pump which makes it adaptable for producing highfluid pressures, and particularly, high liquid pressures which are ofsufllcient value that the pump can be used as the pressure supplymechanism for actuating hydraulic mechanisms. In former vane type pumpsconsiderable difficulty has been encountered in producing high pres-'sures, since the liquid slip past the vane has been considerable. Therehave been attempts to secure the vanes in constant engagement with thecylindrical wall of the cylinder and to increase the volumetricefficiency of vane type Dumps when used for liquid delivery. Theseapplicants have produced a mechanism which promotes the maximumefliciency of a vane type liquid delivery pump and which retains thevanes of the pump in constant engagement with the cylindrical wall ofthe cylinder to prevent liquid slip past the endsof the vanes which arein engagement with the cylinder wall.

It is an object of this invention to provide an improved pump structurefor use as a liquid It is another object of the invention to providemeans for retaining the vanes ofa vane type pump in engagement with thecylindrical wall of the cylinder.

It is another object of the invention to provide 'a mechanism inaccordance with the foregoing object whichresiliently urges the vanesoutwardly into engagement with the cylindrical wall.

It' is another object of the invention to retain thevanes of a vane typepump in engagement with the cylinder wall by means of fluid or liquidunder pressure. X

It is another object of the invention iio provide a vane typeliquiddelivery pump having means for retaining the vanes in constantengagement with the walls of the cylinder, and which cylinder is adaptedto be moved with respect to the pump rotor in order'to change thedirection of delivery of the pump.

It is another object of the invention to provide a variable deliveryreversible flow liquid pump of the vane type having a mechanism iormaintaining the vanes in engagement. with the cylinder wall, and whichis constructed and arranged for movement of the cylinder with respect tothe rotor without effecting the mechanism for maintaining the vanes inconstant engagement with the cylindrical wall of the cylinder.

It is another object of the invention to provide .a variable deliveryreversible flow fluid pump with means for conducting fluid underpressure under the vanes to force the same outwardly intoengagement'with the cylinder walls, wherein means are pr'ovided forchanging the flow of pressure fluid in the conducting means when theflow oi fluid through the pump is reversed.

It is another object of the invention to provide a; vane type fluid pumpwherein the vanes are a loose fit within cooperating slots in the rotorto permit fluid to enter the slots which, when under pressure, willforce the vane outwardlymentioned object wherein the vane can tilt an-,

gularly in either direction with respect to the slot and thesealbetween. the high and low pressure sides will be eflfective ineither position of the vane. Y

It is another object of the invention to providev a variable deliveryreversible flow fluid pump of. v the vane type having vanes which are aloose flt in the rotor slots for the same, and which has the advantagesaforementioned for this type pump. It is another object of the inventionto provide a vane type pump for liquid delivery which has Y astraight-through liquid flow through the pump. Further objects andadvantages will become apparent from the description and the drawings.

In the drawings: Figure 1 is a longitudinal cross-sectional view I ofthe pump of this invention.

Figure 2 is a transverse cross-sectional view of a portion of thepumping mechanism showing a modified arrangement of pumping mechanism.Figure 3 is a perspective elevational view of one of the vanes used inthe pump of Figure 2.

In this invention the fluid or liquid pump consists of. a casing havingpassageways l l and I2 extending therethrough. A substantiallyrectangular member 11 forms a cylinder block within which there isprovided a cylindrical bore 18 which extends transversely of the blockl1. This bore 18 forms the cylinder wallof the cylinder of the pump. Thecylinder block 11 is carried between parallel faces I9 and 20 providedon the casing It, the parallel faces provided on the cylinder block 11slidably engaging the faces l9 and 20 to permit the cylinder block H tobe reciprocated thereon. A passageway 2| provided in the cylinder blockl1 communicates with the passageway II, and a passageway 22 provideddiametrically opposite thepassageway 2| communicates with the passagewayI2.

A rotor member 23 has a body portion 24 pcsitioned within the cylinderbore l8. One side of the body portion 24 carries a flanged portion 25which engages the wall of the cylinder block IT, as indicated at 28. Anend plate 21-is secured to the rotor body 24 by means of the bolts V 28and is adapted to engage the opposite face of the cylinder block 11, asindicated at 29.

The flanged portion 25 of the rotor 23 has a hub 30 extending therefromwhich is carried by the inner. race 3| of a ball bearing 32 which ispositioned within a recess provided in the casing 10. The end plate 21has a hub 34 which carries a bushing 35. The bushing 35 is carried bythe inner race 33 of a ball bearing 31 mounted within a recess 39 of theend plate 40 of the casing 10. The end plate 40 is secured to the casingill by means of the bolts 41 and encloses the pumping mechanism withinthe casing in. The hub 30, on the flanged portion 25, extends outwardlyof the casing 10 and provides a drive shaft 42 which can be suitablyconnected to a driving mechanism, such as an electric motor or any othersuitable power device.

A conventional oil seal 43 is positioned around the drive shaft 42 andis retained within a recess 44 in the casing ill by means of a closureplate The body 24 of the rotor 23 is provided with a plurality of radialslots 46 in each of which there is positioned a vane 41. The vanes 41have their outward ends in engagement with the cylindrical bore l8 andwhich cooperate with the cylindrical bore l3 and the body of the rotor24 to provide means for pumping fluid between the passageways and I2.The vanes 41 have their inner readily be seen that the vanes 41 willextend into the bore 43 in the rotor body 24, and that the extendingportion of eachvane will have a different length according to theposition of the vane with respect to the eccentric positioning of thecylinder bore l8 with respect to the rotor body 24.

In order to retain the vanes 41, in constant engagement with thecylinder bore It a frustoconical pin 501s positioned within the bore 48and is of such diameter that the surface thereof engages a complementarysurface on each .of the inner ends of the vanes 41. Since the vanes 41are all of equal length it can be seen that the pin 50 will be arrangedconcentric with respect to the cylindrical bore l8, and since the endsurfaces 5| of the vanes 41 have'a form complementary to that of pin 50,it can readily be seen that the vanes 41 will remain in constantengagement with the cylindrical bore l8 at all points throughouttheirrotation about the pin 50. The pin 50 thus becomes a member which isfloated by the inner ends of the vanes 41, which provides a rigidbearing surface upon which the vanes ride in order to mechanically urgethe same into constant engagement with the cylindrical bore l8.

These complementary frusto-conical surfaces on the pin 50 and the vanes41 cooperate, as indicated at 52, to provide surfaces by which theradial position of the vanes 41 can be altered. Longitudinal or axialmovement of the pin 50 forces the vanes 41 outwardly to the right asseen in Figure 1 to thereby decrease the clearance between the end ofthe vanes 41 and the cylinder bore I8.

The adjusting means for axially or longitudinally moving the pin 50consists of a cylindrical plunger 53 mounted within a bore 54 providedin the hub 30 of the rotor 23. The plunger 53 extends into the bore 49within the body 24 of the rotor and engages the pin 50, as indicated at55. A compression spring 58 is positioned between the end wall 51 of theplunger 53 and 45 the end wall 58 of the bore 54, which spring tendsends extending within a central bore 48 provided in the rotor body 24.Thebore 43 extends into the flanged portion 25 and a cooperating bore 49is provided in the plate 21. The vanes 41 are all of equal length andsince the cylinder' bore I3 is eccentric with respect to the rotor. body24 when the pump is in operating position, it can to urge the taperedpin 50 to the right, as indicated in Figure 1. The taper on the pin 50extends from the left to the right thereof, viewed in Figure 1, so thatmovement of the pin 50 to the right will tend to force the vanes 41outwardly into engagement with the cylinder bore 7 13. The spring 56thus provides means for resiliently urging the tapered pin 50 intopressure engagement with the vanes 41. A small hole 53a is provided inthe end of the plunger 53 to prevent the plunger from acting as apiston.

An adjusting screw is provided in the end plate 21 and engages afriction button 60 which en-.

gages the righthand end of the tapered pin 5|). The adjusting screw 59is in threaded engagement within the hub 34 of the end plate 21. Aninspection plate BI is provided on'the end plate 40 of the casing III topermit access to the adjusting screw 59. Means for binding the adjustingscrew in position after an adjustment has been made is provided on thehub 34 of the end plate 21 and consists of a portion 62 of the hub whichhas been separated from the main body thereof by means of a slot 63. Ascrew 64 extends through the portion 62 and into threaded engagementwith the body of the hub 34. When the screw 64 is tightened the flangedportion 62 will bind upon the threads of the adjusting screw 59 toretain the same in its properly adjusted position. A drain opening 96 isprovided in the casing I to remove liquid or fluid leaking into thecasing from the pumping mechanism.

The mechanism just described provides a fluid or liquid pump wherein thefluid flow through the pump is an in-line flow, whereby minimumresistance to fluid flow is obtained and which provides a structuralarrangement whereby the .r intle.

' The pump can be operated as a variable delivery pump, or the fluidflow therethrough can be reversed. As previously described the cylinderblock I! is in sliding engagement with the surfaces I0 and of the casingII. The plane of eccentricity of the cylinder bore I0 with respect tothe rotor 23 is parallel to these surfaces I0 and 20 so thatreciprocation of the cylinder block I! parallel to the surfaces I0 and20 alters the eccentricity of the cylinder bore II with respect to thebody 24 of the rotor.

In Figure 2 there is disclosed a modified form of pump rotor which canbe used in the pump previously described. When used in the pumpdescribed with regard to 'Figure 1, the only modiflcation required ofthis pump is the removal of the tapered pin and the operating mechanismfor the same.

This modified form of rotor consists of a rotor body 90 which ispositioned within a cylinder bore 90 provided in a cylinder block 01.Suitable end plates are provided on the rotor 00 for sealing the ends ofthe bore 90 and thereby providing a pumping chamber. The structure ofthese end plates has been previously described and the specific mannerof mounting the same in the pump casing has also been described so thatthe pumping mechanism in this modified .form contains the sameadvantages of minimum of friction developed between the working parts.Suitable bolts 98 extend through the rotor and secure the end platesthereto. I

A plurality of slots 90 extend longitudinally of the rotor 85 and alsoextend radially thereof. Vanes I 00 are adapted to be positioned withinthe slots 98 for reciprocation therein. It is of course understood thatwhen the pump is in operating position the cylinder'bore 90 is eccentricwith respect to the rotor 95, which rotor rotates concentric withrespect to the bearing supportfor the same. It is also understood thatthe cylinder bore 90 is shiftable with respect to the rotor 00 to varythe flow of the pump or to reverse the flow thereof.

The vanes I00 have a cross-sectional dimension which is less inthickness than the width of the slot in which the vane is to operate,thereby providing clearance between the face surface I0l of the vane andthe face surfaces I02 oi the slot. The faces -l0l of the vanes I00 areprovided with an undercut portion toward the lower edge thereof which isangularly disposed with respect to the faces I0-I so that an angularface I0! i provided near the central portion of the lower edge of bothof the faces IN on each of the vanes I00. The outer edge of the face IOIremains rectangularinshapeas shown at I 04.

With the vanes I00 constructed as Just described, it can readily beappreciated that fluid or liquid can pass between the surfaces IN and I02 of the vane and slot and enter the chamber Ill just below the vaneI00, and a the fluid or liquid is under pressure that the pressure ofthe fluid will act upon the end of the vane m to with thee-cylinder bore00.

force the vane I00 outwardly into encasement- However, when the pump nopressure existing on either side thereof the initial rotation of therotor 00 causes the vanes I00 to be moved outwardly due to thecentrifugal force. Also, the rotation of the rotor 05 causes the vanesI00 to assume an angular position with respect to a slot I02 so that theend ofthe vane lags behind the slot thereby providing-a deflnitepassageway I06 between the forward face of the vane I00 and the forwardface of the slot 00 whereby fluid will enter the chamber I05. when thevane I00 assumes this position the rear face of the vane I00 will engagethe upper and rearward edge of the slot 00, as indicated at I01; therebyproviding a sealing engagement there between for sealing the chamber I05from the chamber I08 which trails the vanes I00.) It is understood thateach of the vanes I001 has a chamber in advance thereof and a chamberwhich trails the same, the chamber in advance of the vane being thecompression chamber or fluid moving chamber, while the chamber trailingthe vane is the suction chamber. The pressure in the chamber in advanceof the vane I00 will thus provide a rearward pressure on the vane I00,to cause the rear face thereof to seal against the upper and rearwardedge of the slot 09, which i in direct proportion to the pressure in thechamber in advance of the vane. Since the passage I00 permits fluid orliquid to enter the chamber I0! the vane I00 will be forced outwardlyinto engagement with the cylinder bore 00 by a force which isproportionate to the surface area of the inner edge of the vane exposedto thepressure, this force being relieved to some extend by the pressureexerted on the outer edge, surface of the vane I00. However, since-theinner edge 40 surface of the vane has a greater surface area exposed tothe pressure than the outer surface edge the resultant of the forceswill be such that the vane will be moved outwardly into engagement withthe cylinder wall 96. While the fluid or liquid pressure is also exertedupon the rear face of the vane I00 below the edge I01, yet the surfacearea of the vane exposed to this force is less than the surface areaexposed on the forward face thereof so that the resultant of the forceswill be a rearwardly directed force opposed to the direction of rotationof the rotor.

This condition is true at all points on all vanes of the rotor, with theexception of one position and that is the position of the vane passingover ,the land betweenthe high and low pressure sides of the pump. Whenthe vane is in the land he- Ween the high and low pressure sides of theI pump the pressure from the high side of the the high side of the pump,or in proportion to the pressure existing in the chamber in advance ofeach of the vanes .so that .as the pressure against which the pumpisworking increases, the

is first started with sealing engagement of the vane with the cylinderbore 98 will be increased. Also, by the same course of events, thesealing engagement between the vane and the rearward edge of the slot 99will be increased.

Since the angular face I03 is provided on both sides of each of thevanes I00, it can readily be 7 invention these various mechanicalmodifications.

) This application is a division of my copending application Serial No.377,709, filed February 6,

1941, patented July 18, 1944, No. 2,354,076.

Having thus [fully described our invention, what we claim as new anddesire to secure by Letters Patent is:

A reversible variable delivery pumpincluding, a cylinder having fluidflow passages, a rotor having therein a plurality of radiallyand axiallyextending slots, said rotor being Journaled within said cylinder, saidcylinder and rotor being relatively movable to change the eccentricitybetween their axes, a generally rectangular vanein each slot,respectively, each vane having an axial dimension greater than itsradial dimension, and -a thickness substantially less than thecorresponding dimension of its slot whereby each vane tiltscircumferentially within its slot in a direction depending upon thedirection of rotation of said-rotor, the outer end of each vaneslidably. engaging the walls 01 said cylinder and being shaped to give,when so tilted, substantially line contact along elements of saidcylinder, each vane, when so tilted having substantially line contactwith its slot on opposite sides thereof, each vane having its opposedfaces chamfered along and adjacent a mid-portion of its inner edge,whereby fluid under pressure may have access to the slots when the vanesare so tilted, to thereby urge each vane radially outward.

WARREN R. TUCKER. GEORGE A. WALDIE.

